Light detection and ranging (lidar) is a technology that measures a distance to an object by projecting a laser toward the object and receiving the reflected laser. As a method of measuring a distance in the lidar technology, a time of flight (TOF) which uses a flight time of laser light, a triangulation method which calculates a distance according to a position of a received laser according to a position of a received laser, and the like are used.
The triangulation method measures a distance with respect to a wide range at once mainly by using a flash laser, but has low accuracy, therefore lidar, to which the TOF method capable of performing relatively high definition/high resolution measurement with respect to a long distance, is used as a distance sensor for autonomous vehicles which have recently taken center stage as a significant application field for lidar.
Measurement distance, heat suppression, size reduction, and the like have emerged as main technical issues of lidar using the TOF method. To overcome the issues, a variety of research has been performed.